The common frog is the most common frog , you may come across this frog in any bog or marsh or the side of a river. The futherst west one of these frogs has been sighted is ireland. Adult common frogs range from 6-9 centemetres (2.5-3.7inches). Another intresting fact about common frogs is that they can change their shade of brown according to their surroundings. The tadpoles of common frogs are herbivores but will eat other animals in small parts , once they have grown into an adult frog they will eat live food such as crickets , grasshoppers , flies and small worms.